LOCATION OCALA                   NV

Established Series
Rev. LIL-RAF-JVC-JBF
09/2019

OCALA SERIES

The Ocala series consists of very deep, somewhat poorly drained soils that formed in alluvium derived from mixed rocks with a component of volcanic ash. Ocala soils are on stream terraces, flood plains, lake plains, inset fans, fan skirts, and alluvial flats. Slopes are 0 to 2 percent. The mean annual precipitation is about 180 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Duric Halaquepts

TYPICAL PEDON: Ocala silt loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 3 cm; very pale brown (10YR 8/3) silt loam, brown (10YR 5/3) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine interstitial pores; 1 to 5 mm thick, very hard, salt crust on surface; strongly effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (0 to 15 cm thick)

C--3 to 38 cm; very pale brown (10YR 8/2) silt loam, brown (10YR 5/3) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and moderately plastic; many very fine, few fine and medium roots; few very fine tubular pores; few brittle durinodes; strongly effervescent; very strongly alkaline (pH 9.6); clear smooth boundary. (10 to 46 cm thick)

Ckq1--38 to 48 cm; light gray (10YR 7/2) silt loam, brown 10YR 4/3) moist; massive; hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine and very fine tubular pores; common fine and many medium faint dark brown (10YR 3/3) masses of iron and manganese accumulation; 70 percent 5 to 15 millimeter very hard brittle durinodes; strongly effervescent; strongly alkaline (pH 9.0); gradual smooth boundary. (8 to 20 cm thick)

Ckq2--48 to 58 cm; light gray (10YR 7/2) silt loam, variegated pale brown (10YR 6/3), brown (10YR 5/3), and dark brown (10YR 3/3) moist; massive; hard, firm and brittle, slightly sticky and nonplastic; few very fine roots; common fine and very fine tubular pores; common medium faint dark yellowish brown (10YR 4/4) masses of iron accumulation; strongly effervescent; strongly alkaline (pH 9.0); clear wavy boundary. (8 to 36 cm thick)

Ckq3--58 to 84 cm; light gray (10YR 7/2) silt loam, variegated light brownish gray (10YR 6/2), grayish brown (10YR 5/2), and dark grayish brown (10YR 4/2) moist; moderate medium and thick platy structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine tubular pores; common medium faint brown (7.5YR 4/3) masses of iron accumulation; 50 percent 1 to 5 mm extremely hard, very firm, brittle durinodes; strongly effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (13 to 70 cm thick)

Akqb--84 to 114 cm; light gray (10YR 7/1) silty clay loam, variegated dark grayish brown (10YR 4/2), dark gray (10YR 4/1), and very dark gray (10YR 3/1) moist; massive; hard, friable, moderately sticky and moderately plastic; fine and very fine tubular pores; common fine faint brown (7.5YR 4/2) masses of iron accumulation; 90 percent 5 to 30 mm extremely hard, very firm, brittle durinodes; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (0 to 38 cm thick)

2Ckq--114 to 152 cm; white (10YR 8/1) very fine sandy loam, variegated light brownish gray (10YR 6/2), grayish brown (10YR 5/2), and very dark gray (10YR 3/1) moist; massive; hard, friable, nonsticky and nonplastic; few fine tubular pores; common fine faint dark brown (7.5YR 3/2) masses of iron accumulation; 20 percent 5 to 15 mm very hard, very firm, brittle durinodes and 30 percent extremely hard carbonate nodules; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Lander County, Nevada; approximately 17 miles east of Battle Mountain in Boulder Valley; about 1,500 feet east and 700 feet north of the southwest corner of section 19, T. 33 N., R. 47 E.; USGS Argenta 7.5 minute topographic quadrangle; latitude 40 degrees 42 minutes 54 seconds N and longitude 116 degrees 43 minutes 27 seconds W; WGS84 Decimal Degrees 40.7150000 latitude, -116.7241667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: These soils are usually saturated within depths of 100 for one month or more during most years; typic aridic soil moisture regime.
Mean annual soil temperature: 10 to 12 degrees C.
Depth to horizons with durinodes: 25 to 61 cm.
Reaction: Strongly alkaline or very strongly alkaline (up to pH 9.6).
Salinity and sodicity: These soils are normally strongly saline and strongly sodic within 25 cm of the soil surface. Areas that have been flood-irrigated lack this condition but are salt and sodium affected below this depth.
Secondary carbonates: Concretions are normally below depths of 90 cm but are lacking in some pedons.
Redoximorphic features: Redox concentrations occur as masses of iron accumulation below 30 cm.

Particle-size control section - Clay content: 18 to 35 percent.

A and C horizons
Hue: 10YR through 5Y.
Value: 6 through 8 dry, 4 through 7 moist.
Chroma: 1 through 4, dry or moist.
Structure: Granular or platy.
Salinity (EC): 16 to 32 mmhos/cm.
Sodicity (SAR): 30 to 90.

Ckq and Akqb horizons
Hue: 10YR through 5Y.
Value: 6 through 8 dry, 4 through 7 moist.
Chroma: 1 through 4, dry or moist.
Texture: Silty clay loam or silt loam with thin strata of clay loam, loam, or silty clay in some pedons.
Structure: Moderate to strong platy, massive, angular blocky, prismatic parting to angular blocky.
Consistence: Slightly hard to hard dry, friable to firm and brittle moist. Slightly sticky to very sticky and slightly plastic to very plastic.
Durinodes: Some pedons have horizons with 20 to 70 percent durinodes in a friable matrix above a horizon with firm consistence and a brittle manner of failure.
Salinity (EC): 4 to 16 mmhos/cm.
Sodicity (SAR): 13 to 60.
Other features: Strata or lenses of volcanic ash, up to 10 cm thick, are in most pedons, especially below 76 cm. These ashy strata are usually noncalcareous and slightly alkaline.

COMPETING SERIES: There are no other series in this family.

GEOGRAPHIC SETTING: Ocala soils are on stream terraces, flood plains, lake plains, inset fans, fan skirts, and alluvial flats. These soils formed in alluvium derived from mixed rocks with a component of volcanic ash. Slopes are 0 to 2 percent. Elevations range from 1,180 to 2,070 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 125 to 250 mm, the mean annual temperature is 8 to 11 degrees C, and the frost-free period is 100 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Humboldt, McConnel, Placeritos, and Sonoma soils. Humboldt soils are fine and have mollic epipedons. McConnel soils are sandy-skeletal and do not have endosaturation within a depth of 100 cm. Placeritos soils do not have durinodes. Sonoma soils do not have durinodes and have less than 15 percent exchangeable sodium in half or more of the upper 50 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; medium or high surface runoff; moderately low saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal high water table between 90 and 100 cm (moderately deep free water occurrence class) between February and June. Cumulative annual duration class is Common. The water table ranges from 90 to 150 cm during the peak of the spring runoff period. Originally all of these soils were poorly drained but entrenchment of local streams and isolation due to stream meandering has lowered the water table to depths below 210 cm. Wet, drained, and flooded phases are recognized.

USE AND VEGETATION: Ocala soils are used for livestock grazing and wildlife habitat. In some areas, where water is available, native meadows are irrigated and either cut for hay or pastured. The vegetation is principally black greasewood, rubber rabbitbrush, inland saltgrass, and alkali sacaton in the more saline areas; basin wildrye, creeping wildrye and inland saltgrass are in the less saline areas.

DISTRIBUTION AND EXTENT: Northern and central Nevada. These soils are extensive with about 121,000 acres of the series mapped to date. The series concept and main acreage is in MLRA 24, while other acreage occurs in MLRAs 25 and 28B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Pershing County (Lovelock Area), Nevada, 1963.

REMARKS: The revision of April 2003 updated the taxonomic class from Fine-silty, mixed, superactive, calcareous, mesic Aeric Halaquepts. Future study is needed to determine the amount of volcanic glass in this series and whether the taxonomic class should be changed to Ashy, glassy, calcareous, mesic Aquandic Halaquepts.

Diagnostic horizons and feature recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of the C horizons).
Durinodes - The zone from about 38 to 48 cm and 58 to 152 cm (Ckq1, Ckq3, Akqb, and 2Ckq horizons).
Endosaturation feature - The condition of ground water with an upper boundary between 90 and 150 cm at certain times during normal years (parts of the Akqb and 2Ckq horizons).
Aquic - an apparent seasonal high water table between 90 and 100 cm (part of Akqb Horizon).
Particle-size control section - The zone from 25 to 100 cm (Ckq1, Ckq2, Ckq3 and parts of the C and Akqb horizons).

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National Cooperative Soil Survey
U.S.A.